A rectangle is $7$ centimeters long. The rectangle is also $3$ centimeters wide. What is its perimeter?
Explanation: $7\text{ cm}$ $3\text{ cm}$ The perimeter is the total length of all the sides of the shape added together. Add up the lengths of the sides: $ \text{perimeter} = {3} + {7} + {3} + {7} $ $ \text{perimeter} = 20\text{ cm} $